From patchwork Thu Jan 23 20:59:28 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andreas Noever X-Patchwork-Id: 3531791 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Original-To: patchwork-linux-pci@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id EEDEFC02DC for ; Thu, 23 Jan 2014 21:00:56 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 29F24201C0 for ; Thu, 23 Jan 2014 21:00:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 56464201BB for ; Thu, 23 Jan 2014 21:00:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754464AbaAWVAI (ORCPT ); Thu, 23 Jan 2014 16:00:08 -0500 Received: from mail-wg0-f51.google.com ([74.125.82.51]:48265 "EHLO mail-wg0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754462AbaAWVAG (ORCPT ); Thu, 23 Jan 2014 16:00:06 -0500 Received: by mail-wg0-f51.google.com with SMTP id z12so2096060wgg.18 for ; Thu, 23 Jan 2014 13:00:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=+TemXxYPTzcR15sVyB1U7IghJdOPXREt4Km7x7l8pmw=; b=yMTdh/nJlnc/Q7wSBJ150Q4nGGwkvx/koGDVGDnMKdKTZt9DGv7JJ0iKdv2WwQNRKr Cl1r6mP+hGGjg7Hy85rLdgA+a3LyDk7mj/A/qhZ7l0lOsELH70bTOQ+81KaCbNcon6E6 diLy8+kd1WOi0/i2I3ZdtGsh9jR7RMMbuCUaEmVQPwv/h2uZMbGNviYEh59str82nYUl xd+aX9lL8Wb0CXf4Eo3t+A73GCGlSGFRXG6UNhg9ABCzcZLUHOqR7+/Cm9tJ95bd3dwK ewK+mjEPr4kUoCORo9q7PvWn1PZhSoVy6Mn4MkRKNdQFO2w0sKMkXOUDBHPjaGeAWMBT wWOQ== X-Received: by 10.180.75.202 with SMTP id e10mr710441wiw.50.1390510805011; Thu, 23 Jan 2014 13:00:05 -0800 (PST) Received: from localhost.localdomain (77-58-151-250.dclient.hispeed.ch. [77.58.151.250]) by mx.google.com with ESMTPSA id ux5sm25371408wjc.6.2014.01.23.13.00.04 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 23 Jan 2014 13:00:04 -0800 (PST) From: Andreas Noever To: linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, bhelgaas@google.com Cc: Andreas Noever Subject: [PATCH 8/8] PCI: Don't scan random busses in pci_scan_bridge. Date: Thu, 23 Jan 2014 21:59:28 +0100 Message-Id: <1390510768-5652-9-git-send-email-andreas.noever@gmail.com> X-Mailer: git-send-email 1.8.5.3 In-Reply-To: <1390510768-5652-1-git-send-email-andreas.noever@gmail.com> References: <1390510768-5652-1-git-send-email-andreas.noever@gmail.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Spam-Status: No, score=-7.3 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, T_DKIM_INVALID, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When assigning a new bus number in pci_scan_bridge we check whether max+1 is free by calling pci_find_bus. If it does already exists then we assume that we are rescanning and that this is the right bus to scan. This is fragile. If max+1 lies outside of bus->busn_res.end then we will rescan some random bus from somewhere else in the hierachy. This patch checks for this case and prints a warning. Signed-off-by: Andreas Noever --- drivers/pci/probe.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 74bc644..0a94de2 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -830,12 +830,16 @@ int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, int pass) goto out; } + if (max >= bus->busn_res.end) { + dev_warn(&dev->dev, + "parent bus ran out of bus numbers, cannot allocate child bus\n"); + goto out; + } + /* Clear errors */ pci_write_config_word(dev, PCI_STATUS, 0xffff); - /* Prevent assigning a bus number that already exists. - * This can happen when a bridge is hot-plugged, so in - * this case we only re-scan this bus. */ + /* The bus will already exist if we are rescanning */ child = pci_find_bus(pci_domain_nr(bus), max+1); if (!child) { child = pci_add_new_bus(bus, dev, max+1);